Two different Alk

[MichaelReefer]

So I am very good friends with the owners of my LFS and get about bi monthly water tests on a API Aquaspin that they have for free. I noticed that my alk is always lower on the Aquaspin than my Hanna shows. It showed 7.9 on the Aquaspin, but my Hannah shows 9.0. I dont know if its the transportation of the water in the tubberware to the LFS or if my Hanna is that much off? Has anyone had any experience with this? It's hard to believe that a professional quality tester that costs over $1200 could be off that much, so I wonder if it's me?

 

[vetteguy53081]

Unfortunately API is notorious for false readings and I assume this is another case of such
I’d go with Hanna readings aquaspin was originally a pond tester in which they transferred the technology to aquarium use

 

[MichaelReefer]

Unfortunately API is notorious for false readings and I assume this is another case of such
I’d go with Hanna readings aquaspin was originally a pond tester in which they transferred the technology to aquarium use

Interesting. Yeah, for something so expensive you would think its dead on. Most of the other numbers come up fairly close to what my testing shows but the alk is always way off.

 

[nereefpat]

Alk tests of different brands often don't line up. It doesn't necessarily mean that either is wrong or right. Shoot for consistency.

I hadn't heard of the API Aquaspin until now. I personally don't like either that or the Hanna for checking alk, as I don't see how a colorimeter can possibly give you accurate results for something that should be a titration. I would actually trust a standard API kit over either of these methods. People here really like the Salifert kit; it seems to be the most popular one. It is a titration too.